(a) Field of the Invention
The present description relates to a method and apparatus for receiving a reference signal in a mobile communication system.
(b) Description of the Related Art
A downlink reference signal (RS) of LTE (long term evolution) system includes Cell specific RS (CRS), User Equipment RS (UE-RS), positioning RS (PRS), and channel state information-RS (CSI-RS). Because the UE-RS is transmitted as UE-specific physical downlink shared channel (PDSCH), the UE-RS exists in a physical resource block (PRB) included in downlink bandwidth allocated to terminal through downlink grant (DL grant), not in the remaining of PRB pair that are not indicated in the DL grant. The rest of downlink RS (CRS, PRS, CSI-RS) is transmitted periodically on the entire PRB pairs included in the system bandwidth. Then, the terminal may obtain CSI (that is, precoding matrix indicator (PMI)/rank indicator (RI)/channel quality indicator (CQI)/CSI-RS resource indicator (CRI)/Precoding matrix type indicator (PTI)) using the CSI-RS on the CSI reference resource defined by the LTE specification. Afterwards the obtained CSI by the terminal from the CSI-RS may be reported according to the CSI reporting mode defined by the LTE specification.